Injector for injecting fluid

Abstract

An injector for injecting fluid includes a valve needle axially moveable with respect to a valve body and operable to prevent a fluid injection in a closing position and to permit the fluid injection in an open position, an armature for moving the valve needle in a first direction from the closing position towards the open position, a needle retainer fixed to the valve needle, and an armature holder fixed to the armature, wherein the needle retainer and the armature holder are releasably coupleable such that when the armature moves in the first direction the needle is moved in the first direction by the movement of the armature holder and the needle retainer.

What is claimed is: 
     
       1. An injector for injecting fluid, comprising:
 a valve body having a longitudinal axis, 
 a valve needle axially moveable along the longitudinal axis of the valve body to prevent a fluid injection in a closing position and to permit a fluid injection in an open position, 
 an armature configured to move the valve needle in a first direction from the closing position towards the open position, 
 a valve needle spring biased to move the valve needle in a second direction from the open position towards the closing position, 
 a L-shaped needle retainer having first and second portions, a first needle retainer portion elongated in the direction of the longitudinal axis fixed to the valve needle and a second needle retainer portion elongated in a direction perpendicular to the longitudinal axis, the second needle retainer portion having top and bottom sides defining top and bottom contact areas on either side for contact with the armature on the top side and contact with an armature holder on the bottom side, and 
 a L-shaped armature holder having first and second portions, a first armature holder portion elongated in the direction of the longitudinal axis fixed to the armature and a second armature holder portion elongated in a direction perpendicular to the longitudinal axis, the second armature holder portion having top and bottom sides defining a contact area on the top side for contacting the bottom side of the second needle retainer portion, 
 wherein the needle retainer and the armature holder are releasably coupleable upon the armature moving towards the first direction, such that the needle is also moved towards the first direction by the movement of the armature holder in contact with the needle retainer, and 
 the needle retainer and the armature holder are de-coupleable upon the valve needle moving towards the second direction, with the movement of the needle in the second direction limited by contact of the bottom side of the second needle retainer portion with the top side of the second armature holder portion. 
 
     
     
       2. The injector according to  claim 1 , comprising a welded connection between the armature holder and the armature that fixes the armature holder to the armature. 
     
     
       3. The injector according to  claim 1 , comprising a welded connection between the needle retainer and the valve needle that fixes the needle retainer to the valve needle. 
     
     
       4. The injector according to  claim 1 , further comprising a further spring between the needle retainer and the armature. 
     
     
       5. The injector according to  claim 1 , wherein the needle guide is fixed to the needle such that a free space is arranged between the needle guide and the armature during a movement of the armature in the first direction. 
     
     
       6. An internal combustion engine of a vehicle, comprising:
 at least one cylinder; 
 an injector arranged for injecting fluid into each cylinder, each injector comprising: 
 a valve body having a longitudinal axis, 
 a valve needle axially moveable along the longitudinal axis of the valve body to prevent a fluid injection in a closing position and to permit a fluid injection in an open position, 
 an armature configured to move the valve needle in a first direction from the closing position towards the open position, 
 a valve needle spring biased to move a valve needle in a second direction from the open position towards the closing position, 
 a L-shaped needle retainer having first and second portions, a first needle retainer portion elongated in the direction of the longitudinal axis fixed to the valve needle and a second needle retainer portion elongated in a direction perpendicular to the longitudinal axis, the second needle retainer portion having top and bottom sides defining top and bottom contact areas on either side for contact with the armature on the top side and contact with an armature holder on the bottom side, and 
 a L-shaped armature holder having first and second portions, a first armature holder portion elongated in the direction of the longitudinal axis fixed to the armature and a second armature holder portion elongated in a direction perpendicular to the longitudinal axis, the second armature holder portion having top and bottom sides defining a contact area on the top side for contacting the bottom side of the second needle retainer portion, 
 wherein the needle retainer and the armature holder are releasably coupleable upon the armature moving towards the first direction, such that the needle is also moved towards the first direction by the movement of the armature holder in contact with the needle retainer, and 
 the needle retainer and the armature holder are de-coupleable upon the valve needle moving towards the second direction, with the movement of the needle in the second direction limited by contact of the bottom side of the second needle retainer portion with the top side of the second armature holder portion. 
 
     
     
       7. The engine according to  claim 6 , comprising a welded connection between the armature holder and the armature that fixes the armature holder to the armature. 
     
     
       8. The engine according to  claim 6 , comprising a welded connection between the needle retainer and the valve needle that fixes the needle retainer to the valve needle. 
     
     
       9. The engine according to  claim 6 , further comprising a further spring between the needle retainer and the armature. 
     
     
       10. The engine according to  claim 6 , wherein the needle guide that is fixed to the needle such that a free space is arranged between the needle guide and the armature during a movement of the armature in the first direction.